Add Secure Boot signing guide

[Cuda-Chen]

Add Secure Boot signing guide.

---

Summary by cubic

Add a Secure Boot signing guide and link it from the README so users can load simplefs.ko on UEFI Secure Boot systems. The guide shows Ubuntu commands to install linux-headers-$(uname -r), mokutil, kmod, and openssl; generate and enroll a MOK key via mokutil/MOK Manager; sign the module and verify with modinfo—with the README noting disabling Secure Boot as an alternative.

^{Written for commit 06da008. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 2 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="README.md">

<violation number="1" location="README.md:36">
P3: New Secure Boot sentence contains grammar errors that hurt readability</violation>
</file>

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P3: New Secure Boot sentence contains grammar errors that hurt readability

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At README.md, line 36:

<comment>New Secure Boot sentence contains grammar errors that hurt readability</comment>

<file context>
@@ -33,6 +33,9 @@ You can build the kernel module and tool with `make`.
 Generate test image via `make test.img`, which creates a zeroed file of 50 MiB.
 
 You can then mount this image on a system with the simplefs kernel module installed.
+As nowadays many computer enables UEFI Secure Boot, you can either disable Secure Boot
+or sign the kernel module. To sign the module, refer to [secure-boot-signing-guide.md](./secure-boot-signing-guide.md).
+
</file context>

Suggested change

	As nowadays many computer enables UEFI Secure Boot, you can either disable Secure Boot
	+As many computers now have UEFI Secure Boot enabled, you can either disable Secure Boot
	or sign the kernel module. To sign the module, refer to [secure-boot-signing-guide.md](./secure-boot-signing-guide.md).